package Lab02.test28;


import java.util.Scanner;

public class Test {
    public static void main(String[] args) {
        Scanner scanner=new Scanner(System.in);
        System.out.println("请输入圆的半径：");
        int r=Integer.parseInt(scanner.next()); //获取半径
        System.out.println("圆的面积为:"+Math.PI*r*r);
    }
}
